Alternative paths to alcohols and hydrocarbons from biomass

ABSTRACT

A method of producing alcohols, hydrocarbons, or both from biomass, the method including converting biomass into a carboxylic acid; reacting the carboxylic acid with an olefin to produce an ester; and hydrogenolyzing the ester to produce alcohol. The steps of reacting the carboxylic acid with an olefin to produce an ester, and hydrogenolyzing the ester to produce an alcohol, may both be carried out in the same reactor.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.12/629,285, filed Dec. 2, 2009 (now U.S. Pat. No. 8,232,440, issued Jul.31, 2012), which claims the benefit under 35 U.S.C. §119(e) of U.S.Provisional Patent Application No. 61/119,250, which was filed Dec. 2,2008. The disclosures of said applications are hereby incorporatedherein by reference in their entirety for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

BACKGROUND

1. Technical Field

This disclosure relates to biomass. More particularly, this disclosurerelates to alternative paths to alcohols and hydrocarbons from biomass.

2. Background of the Invention

Biomass is biological material that can be converted into fuel. Biofuelsmay be produced from most biological, carbon sources. For example,biofuels may be produced from sources such as photosynthetic plants.Biofuels may be used in a wide variety of applications, such as forcooking, heating, and transportation.

There are many technologies that produce biofuels from biomass. Forexample, ethanol may be produced from lignocellulosic biomass. Enzymaticproduction of free sugars from biomass has been reported. The sugars arethen directly fermented to ethanol. Also in the prior art isgasification of biomass to synthesis gas (CO and H₂), which is directlyfermented to ethanol, or may be catalytically converted to mixedalcohols. Various technologies enzymatically produce free sugars frombiomass, and the sugars are subsequently fermented to acetic acid usinghomoacetogens. The acetic acid may subsequently be hydrogenated toethanol using the methods described in U.S. Pat. Nos. 6,927,048 and7,351,559.

Routes to hydrocarbons include the following: alcohols produced by theabove methods can be converted to hydrocarbons using a zeolite catalyst;synthesis gas produced by gasifying biomass can be converted tohydrocarbons by using a Fisher-Tropsch catalyst; sugars may becatalytically converted to hydrocarbons; and biomass may be converted tohydrocarbons by pyrolysis.

Although various technologies exist for producing biofuels from biomass,there is a need in the art for new, improved more efficient systems andprocesses for the production of alcohols and/or hydrocarbons frombiomass.

SUMMARY

Herein disclosed is a method of producing alcohols, hydrocarbons, orboth from biomass by converting biomass into a carboxylic acid, reactingthe carboxylic acid with an olefin to produce an ester, andhydrogenolyzing the ester to produce alcohol. In embodiments, reactingthe carboxylic acid with an olefin to produce an ester andhydrogenolyzing the ester to produce an alcohol are carried out in thesame reactor. In embodiments, reacting the carboxylic acid with anolefin to produce an ester and hydrogenolyzing the ester to produce analcohol are carried out with one catalyst.

In embodiments, the method further comprises dehydrating at least aportion of the alcohol to produce an olefin feed, at least a portion ofthe olefin feed providing the olefin that reacts with the carboxylicacid to produce the ester. In embodiments, reacting the carboxylic acidwith an olefin to produce an ester and hydrogenolyzing the ester toproduce an alcohol are carried out in the same reactor. In embodiments,reacting the carboxylic acid with an olefin to produce an ester andhydrogenolyzing the ester to produce an alcohol are carried out with onecatalyst. The method may further comprise oligomerizing at least anotherportion of the alcohol to produce hydrocarbons. The method may furthercomprise oligomerizing at least another portion of the olefin feed toproduce hydrocarbons.

In embodiments, the method further comprises oligomerizing at least aportion of the alcohol to produce an olefin feed, at least a portion ofthe olefin feed providing the olefin that reacts with the carboxylicacid to produce the ester. The method may further comprise oligomerizingat least a portion of the alcohol to produce hydrocarbons. Inembodiments, reacting the carboxylic acid with an olefin to produce anester and hydrogenolyzing the ester to produce an alcohol are carriedout in the same reactor. In embodiments, reacting the carboxylic acidwith an olefin to produce an ester and hydrogenolyzing the ester toproduce an alcohol are carried out with one catalyst. Such method mayfurther comprise oligomerizing at least another portion of the alcoholto produce an olefin feed, at least a portion of the olefin feedproviding the olefin that reacts with the carboxylic acid to produce theester.

In embodiments, converting the biomass into a carboxylic acid furthercomprises fermenting the biomass to yield a liquid fermentation brothcomprising water and carboxylate salts, dewatering the liquidfermentation broth to separate the water from the carboxylate salts, andconverting the carboxylate salts into carboxylic acids.

In embodiments, the method further comprises converting the alcohol intoa hydrocarbon. In such embodiments, reacting the carboxylic acid with anolefin to produce an ester and hydrogenolyzing the ester to produce analcohol may be carried out in the same reactor. In such embodiments,reacting the carboxylic acid with an olefin to produce an ester andhydrogenolyzing the ester to produce an alcohol may be carried out withone catalyst. Converting the alcohol into a hydrocarbon can comprise anoligomerization process. In embodiments, converting the alcohol into ahydrocarbon comprises oligomerizing at least a portion of the alcohol toproduce the hydrocarbon. In embodiments, converting the alcohol into ahydrocarbon comprises dehydrating at least a portion of the alcohol toproduce an olefin feed, and oligomerizing at least a portion of theolefin feed to produce the hydrocarbon.

Also disclosed is a method of producing hydrocarbons from biomass byconverting at least a portion of the biomass into a carboxylic acid, aketone, or an ammonium carboxylate salt, reacting at least one of aportion of the carboxylic acid, a portion of the ketone, or a portion ofthe ammonium carboxylate salt in an oligomerization reactor as at leastpart of a process that produces an oligomerization product, andseparating hydrocarbons from the oligomerization product. Inembodiments, the method further comprises converting another portion ofthe carboxylic acid, another portion of the ketone, or another portionof the ammonium carboxylate salt to alcohol, and providing at least aportion of the alcohol to the oligomerization reactor for the processthat produces the oligomerization product. Converting the anotherportion of the carboxylic acid into alcohol may comprise reacting theanother portion of the carboxylic acid with an olefin to produce anester; and hydrogenolyzing the ester to produce the alcohol. Reacting atleast one of the portion of the carboxylic acid, the portion of theketone, or the portion of the ammonium carboxylate salt in theoligomerization reactor as at least part of the process that producesthe oligomerization product and converting the another portion of thecarboxylic acid, the another portion of the ketone, or the anotherportion of the ammonium carboxylate salt to alcohol can be carried outin the oligomerization reactor. Reacting at least one of the portion ofthe carboxylic acid, the portion of the ketone, or the portion of theammonium carboxylate salt in the oligomerization reactor as at leastpart of the process that produces the oligomerization product andconverting the another portion of the carboxylic acid, the anotherportion of the ketone, or the another portion of the ammoniumcarboxylate salt to alcohol may be carried out with one catalyst.

The method may further comprise separating a recycle stream from theoligomerization product, processing the recycle stream in a reformer toproduce hydrogen, and providing a least a portion of the producedhydrogen for the process of converting the another portion of thecarboxylic acid, the another portion of the ketone, or the anotherportion of the ammonium carboxylate salt to alcohol. In embodimentswherein at least a portion of the biomass is converted to the ammoniumcarboxylate salt, the method may further comprise separating ammoniafrom the recycle stream prior to processing the recycle stream in areformer to produce hydrogen. In embodiments, the method furthercomprises separating olefins from the recycle stream prior to processingthe recycle stream in a reformer to produce hydrogen, and providing theolefins to the oligomerization reactor for the process that produces theoligomerization product. In embodiments, at least a portion of thebiomass is converted to an ammonium carboxylate salt, and the methodfurther comprises separating ammonia from the recycle stream prior toprocessing the recycle stream in a reformer to produce hydrogen.

In embodiments, the method further comprises separating a recycle streamfrom the oligomerization product, separating olefins from the recyclestream, and providing the olefins to the oligomerization reactor for theprocess that produces the oligomerization product.

In embodiments, at least a portion of the biomass is converted into acarboxylic acid. Converting at least a portion of the biomass into acarboxylic acid may comprise fermenting the biomass to produce a calciumcarboxylate salt or an ammonium carboxylate salt, and converting thecalcium carboxylate salt or the ammonium carboxylate salt to carboxylicacid using an acid recovery process.

In embodiments, at least a portion of the biomass is converted into aketone. Converting at least a portion of the biomass into a ketone maycomprise fermenting the biomass to produce a calcium carboxylate salt,and thermally converting the calcium carboxylate salt into the ketone.In embodiments, converting at least a portion of the biomass into aketone comprises fermenting the biomass to produce a calcium carboxylatesalt or an ammonium carboxylate salt, converting the calcium carboxylatesalt or the ammonium carboxylate salt to carboxylic acid using an acidrecovery process, and catalytically converting carboxylic acid intoketone. In embodiments, the method further comprises converting anotherportion of the ketone into alcohol by hydrogenating the another portionof the ketone.

In embodiments, converting at least a portion of the biomass into aketone comprises fermenting the biomass to produce a calcium carboxylatesalt, and producing hot ketone vapors and calcium carbonate in a ketonereactor operated with a sweep gas. The sweep gas can be reactive,condensable or both. In embodiments, the sweep gas comprises hydrogen.In embodiments, the sweep gas comprises steam.

In embodiments, at least a portion of the biomass is converted into theammonium carboxylate salt. Such a method may further comprise convertinganother portion of the ammonium carboxylate salt to alcohol, andproviding the alcohol to the oligomerization reactor for the processthat produces the oligomerization product, wherein converting theanother portion of the ammonium carboxylate salt into alcohol comprisesconverting the another portion of the ammonium carboxylate salt into asecond carboxylic acid, reacting the second carboxylic acid with anolefin to produce an ester, and hydrogenolyzing the ester to produce thealcohol. In embodiments wherein at least a portion of the biomass isconverted into the ammonium carboxylate salt, the method may furthercomprise separating ammonia from the ammonium carboxylate salt prior toreacting the portion of the ammonium carboxylate salt in theoligomerization reactor as at least part of the process that producesthe oligomerization product.

In embodiments, converting at least a portion of the biomass into acarboxylic acid, a ketone, or an ammonium carboxylate salt comprises afermentation process in a fermenter, and the method further comprisesseparating a gaseous recycle stream from the oligomerization product andproviding at least a portion of the gaseous recycle stream to thefermenter. The method may further comprise converting another portion ofthe carboxylic acid, another portion of the ketone, or another portionof the ammonium carboxylate salt to alcohol, and providing the alcoholto the oligomerization reactor. In some such embodiments, at least aportion of the biomass is converted into a carboxylic acid. In some suchembodiments, at least a portion of the biomass is converted into aketone. In some such embodiments, at least a portion of the biomass isconverted into an ammonium carboxylate salt. Such a method may furthercomprise separating ammonia from the gaseous recycle stream prior toproviding the at least a portion of the gaseous recycle stream to thefermenter.

In embodiments, reacting at least one of the portion of the carboxylicacid, the portion of the ketone, or the portion of the ammoniumcarboxylate salt in the oligomerization reactor as at least part of theprocess that produces the oligomerization product and converting theanother portion of the carboxylic acid, the another portion of theketone, or the another portion of the ammonium carboxylate salt toalcohol are carried out in the oligomerization reactor. Reacting atleast one of the portion of the carboxylic acid, the portion of theketone, or the portion of the ammonium carboxylate salt in theoligomerization reactor as at least part of the process that producesthe oligomerization product and converting the another portion of thecarboxylic acid, the another portion of the ketone, or the anotherportion of the ammonium carboxylate salt to alcohol can be carried outwith one catalyst.

In embodiments, the method further comprises separating fermenter gasesexiting the fermenter, processing the fermenter gases in a reformer toproduce hydrogen, and providing a least a portion of the producedhydrogen for the process of converting the another portion of thecarboxylic acid, the another portion of the ketone, or the anotherportion of the ammonium carboxylate salt to alcohol.

Although specific advantages are enumerated herein, various embodimentsmay include all, some, or none of the enumerated advantages.Additionally, other technical advantages may become readily apparent toone of ordinary skill in the art after review of the following figuresand description.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of example embodiments of the presentinvention and its advantages, reference is now made to the followingdescription, taken in conjunction with the accompanying drawings, inwhich:

FIGS. 1A and 1B are block diagrams of calcium and ammonia-based biomassconversion systems respectively, according to embodiments;

FIG. 2 is a block diagram showing conversion of carboxylic acids toalcohols, according to an embodiment;

FIG. 3 is a block diagram showing details of a conversion of carboxylicacids to alcohols, according to an embodiment;

FIG. 4 is a block diagram showing conversion of carboxylic acids toalcohols in one single reactor, according to an embodiment;

FIG. 5 is a block diagram showing details of a conversion of carboxylicacids to alcohols in one single reactor, according to an embodiment;

FIG. 6 is a block diagram showing conversion of carboxylic acids tohydrocarbons via olefin and alcohol (Option A), according to anembodiment;

FIG. 7 is a block diagram showing details of a conversion of carboxylicacids to hydrocarbons via olefin and alcohol (Option A), according to anembodiment;

FIG. 8 is a block diagram showing conversion of carboxylic acids tohydrocarbons via olefin and alcohol with the alcohol produced in onesingle reactor (Option A), according to an embodiment;

FIG. 9 is a block diagram showing details of a conversion of carboxylicacids to hydrocarbons via olefin and alcohol with the alcohol producedin one single reactor (Option A), according to an embodiment;

FIG. 10 is a block diagram showing conversion of carboxylic acids tohydrocarbons via olefin and alcohol (Option B), according to anembodiment;

FIG. 11 is a block diagram showing details of a conversion of carboxylicacids to hydrocarbons via olefin and alcohol (Option B), according to anembodiment;

FIG. 12 is a block diagram showing conversion of carboxylic acids tohydrocarbons via olefin and alcohol with the alcohol produced in onesingle reactor (Option B), according to an embodiment;

FIG. 13 is a block diagram showing details of a conversion of carboxylicacids to hydrocarbons via olefin and alcohol with the alcohol producedin one single reactor (Option B), according to an embodiment;

FIG. 14 is a block diagram showing conversion of carboxylic acids tohydrocarbons via olefin and alcohol (Option C), according to anembodiment;

FIG. 15 is a block diagram showing details of a conversion of carboxylicacids to hydrocarbons via olefin and alcohol (Option C), according to anembodiment;

FIG. 16 is a block diagram showing conversion of carboxylic acids tohydrocarbons via olefin and alcohol with the alcohol produced in onesingle reactor (Option C), according to an embodiment;

FIG. 17 is a block diagram showing details of a conversion of carboxylicacids to hydrocarbons via olefin and alcohol with the alcohol producedin one single reactor (Option C), according to an embodiment;

FIG. 18 is a block diagram showing direct conversion of carboxylic acidsor ketones to hydrocarbons (Option A1), according to an embodiment;

FIG. 19 is a block diagram showing direct conversion of carboxylic acidsor ketones to hydrocarbons (Option B1), according to an embodiment;

FIG. 20 is a block diagram showing direct conversion of carboxylic acidsor ketones to hydrocarbons (Option A2), according to an embodiment;

FIG. 21 is a block diagram showing direct conversion of carboxylic acidsor ketones to hydrocarbons (Option B2), according to an embodiment;

FIG. 22 is a block diagram showing details of conversion of carboxylicacids or ketones to hydrocarbons (Options A2 and B2), according to anembodiment;

FIG. 23 is a block diagram showing fermentation with direct conversionof ketones to hydrocarbons, according to an embodiment;

FIG. 24 is a block diagram showing fermentation with direct conversionof ketones to hydrocarbons with hydrogenation and oligomerizationoccurring in the same reactor, according to an embodiment;

FIG. 25 is a block diagram showing complete biomass conversion forcalcium-based systems, according to embodiments;

FIG. 26 is a block diagram showing the use of sweep gas and the directintroduction of ketone vapors from a ketone reactor to downstream unitoperations, according to an embodiment;

FIG. 27 is a block diagram showing fermentation with direct conversionof carboxylic acids to hydrocarbons, according to an embodiment;

FIG. 28 is a block diagram showing fermentation with direct conversionof carboxylic acids to hydrocarbons with hydrogenation andoligomerization occurring in the same reactor, according to anembodiment;

FIG. 29 is a block diagram showing direct conversion of ammoniumcarboxylate salts to hydrocarbons (Option A1), according to anembodiment;

FIG. 30 is a block diagram showing direct conversion of ammoniumcarboxylate salts to hydrocarbons (Option B1), according to anembodiment;

FIG. 31 is a block diagram showing direct conversion of ammoniumcarboxylate salts to hydrocarbons (Option A2), according to anembodiment;

FIG. 32 is a block diagram showing direct conversion of ammoniumcarboxylate salts to hydrocarbons (Option B2), according to anembodiment;

FIG. 33 is a block diagram showing details of a conversion of ammoniumcarboxylate salts to hydrocarbons (Option A2 and B2), according to anembodiment;

FIG. 34 is a block diagram showing fermentation with direct conversionof ammonium carboxylate salts to hydrocarbons, according to anembodiment;

FIG. 35 is a block diagram showing fermentation with direct conversionof ammonium carboxylate salts to hydrocarbons with hydrogenation andoligomerization occurring in the same reactor, according to anembodiment;

FIG. 36 is a block diagram showing direct conversion of ammoniumcarboxylate salts to hydrocarbons with prior removal of ammonia (OptionA1), according to an embodiment;

FIG. 37 is a block diagram showing direct conversion of ammoniumcarboxylate salts to hydrocarbons with prior removal of ammonia (OptionB1), according to an embodiment;

FIG. 38 is a block diagram showing direct conversion of ammoniumcarboxylate salts to hydrocarbons with prior removal of ammonia (OptionA2), according to an embodiment;

FIG. 39 is a block diagram showing direct conversion of ammoniumcarboxylate salts to hydrocarbons with prior removal of ammonia (OptionB2), according to an embodiment;

FIG. 40 is a block diagram showing details of a conversion of ammoniumcarboxylate salts to hydrocarbons with prior removal of ammonia (OptionA2 and B2), according to an embodiment;

FIG. 41 is block diagram showing fermentation with direct conversion ofammonium carboxylate salts to hydrocarbons with ammonia removal prior tooligomerization, according to an embodiment;

FIG. 42 is a block diagram showing fermentation with direct conversionof ammonium carboxylate salts to hydrocarbons with hydrogenation andoligomerization occurring in the same reactor with removal of ammoniaprior to the oligomerization, according to an embodiment;

FIG. 43 illustrates the liquid-phase product distribution as a functionof hydrocarbon type and number of carbons for isopropanololigomerization over H-ZSM-5 zeolite (Si/Al ratio 280), according to oneexample embodiment;

FIG. 44 illustrates the liquid-phase product distribution as a functionof hydrocarbon type and number of carbons for acetone oligomerizationover H-ZSM-5 zeolite (Si/Al ratio 30), according to one exampleembodiment;

FIG. 45 illustrates the liquid-phase product distribution as a functionof hydrocarbon type and number of carbons for acetone oligomerizationover H-ZSM-5 zeolite (Si/Al ratio 280) at 330° C., according to oneexample embodiment;

FIG. 46 illustrates the liquid-phase product distribution as a functionof hydrocarbon type and number of carbons for acetone oligomerizationover H-ZSM-5 zeolite (Si/Al ratio 280) at 400° C., according to oneexample embodiment;

FIG. 47 illustrates the liquid-phase product distribution as a functionof hydrocarbon type and number of carbons for acetone and hydrogenoligomerization over H-ZSM-5 zeolite (Si/Al ratio 280), according to oneexample embodiment;

FIG. 48 illustrates the liquid-phase product distribution for aceticacid oligomerization over H-ZSM-5 zeolite (Si/Al ratio 280), accordingto one example embodiment;

FIG. 49 illustrates the liquid-phase distribution for acetic acid andhydrogen oligomerization over H-ZSM-5 zeolite (Si/Al ratio 280),according to one example embodiment; and

FIG. 50 illustrates the liquid-phase distribution for ammonium acetateoligomerization over H-ZSM-5 zeolite (Si/Al ratio 280), according to oneexample embodiment.

DETAILED DESCRIPTION

Herein disclosed are systems and methods of producing alcohols and/orhydrocarbons from biomass. In accordance with an embodiment of thisdisclosure, a method of producing alcohols or hydrocarbons from biomassincludes converting biomass into a carboxylic acid. The carboxylic acidis reacted with an olefin to produce an ester. The ester ishydrogenolyzed to produce alcohol. The alcohol can then be oligomerizedto produce hydrocarbons.

Certain embodiments of this disclosure may provide technical advantages.For example, a technical advantage of one embodiment may include thecapability to convert biomass-derived compounds (i.e., carboxylatesalts, carboxylic acids, or ketones) to fuels (alcohols, hydrocarbons).Other technical advantages of other embodiments may include a route toethanol from biomass, prior to hydrogenolysis, reacting carboxylic acidswith an olefin rather than with an alcohol (as is more commonly done),thereby avoiding or minimizing the formation of water in the reaction.Yet other technical advantages of other embodiments may include a routeto ethanol from biomass, reacting carboxylic acids with an olefin in thepresence of hydrogen in the same reactor and with the same catalyst,thus producing alcohols in one step rather than two and avoiding orminimizing the formation of water in the reaction. Yet other technicaladvantages of other embodiments may include adding hydrogen to thereaction of ketones or carboxylic acids for producing hydrocarbons. Yetother technical advantages of other embodiments may include a directconversion into hydrocarbons of ammonium carboxylate salts, which havebeen generated by fermentation of biomass, with and without the additionof hydrogen.

It should be understood at the outset that, although exampleimplementations of embodiments are illustrated below, the systems andmethods of this disclosure may be implemented using any number oftechniques, whether currently known or not. The present invention shouldin no way be limited to the example implementations, drawings, andtechniques illustrated below. Additionally, the drawings are notnecessarily drawn to scale and may not illustrate obvious pieces ofequipment such as valves and instrumentation.

Routes to alcohols and hydrocarbons, according to teachings of certainembodiments will be described below. Examples of catalysts and operatingconditions that may be utilized in various embodiments are presented inTables I-V below.

TABLE I Esterification of Carboxylic Acids and Olefin TemperaturePressure Catalyst (° C.) (kPa) Reference solid acid catalysts 50 to 300450 to 21,000 U.S. Pat. No. (MCM-22, MCM-49, 200 to 250 2200 to 11,0005,973,193 MCM-56, ZSM-5, (preferable) (preferable) zeolite-Beta)

TABLE II Hydrogenolysis of Ester Temperature Pressure Catalyst (° C.)(kPa) Reference Copper chromite >200 >4,100 widely used in industry(e.g., for making detergent alcohols from fatty acids) Reduced CuO—ZnO~150 <2,400 World Patent WO catalyst 82/03854

TABLE III Dehydration of Alcohol to Olefin Temperature Pressure Catalyst(° C.) (kPa) Reference ZSM-5 zeolite  20-760 U.S. Pat. No. 4,011,278Molecular sieve catalyst  200-1000 0.1 to 5,000 USPTO Patent compositioncomprises a 350-550 20 to 500 Application molecular sieve selected(preferable) (preferable) 20060149109 from the group consisting of:SAPO-5, SAPO-8, SAPO-11, SAPO-16, SAPO-17, SAPO-18, SAPO-20, SAPO-31,SAPO-34, SAPO-35, SAPO-36, SAPO-37, SAPO-40, SAPO-41, SAPO-42, SAPO-44,SAPO-47, SAPO-56, AEI/CHA intergrowths, metal containing forms thereof,intergrown forms thereof, and mixtures thereof Solid acid catalysts(e.g., 180-300 ~100 a. zeolites, silica- alumina) γ-Al₂O₃ catalyst410-440 b. HZSM-5 zeolite modified Various c. with Fe, Mn and Cotemperatures (optimal 220° C.) Alumina, titania, and <400 d.alumina-titania hydrogels catalysts High-silica zeolite, high- <400 e.silica zeolite with Fe ZSM-5 zeolite modified 400 f. with Zn and MnClinoptilolite zeolite 350 South African modified by contact with PatentZA 8907621 NaOH and HCl HZSM-5 zeolite modified <300 g. by Mg, Ca, Baand Sr. a. Isao Takahara, Masahiro Saito, Megumu Inaba, Kazuhisa Murata,“Dehydration of ethanol into ethylene over solid acid catalysts,”Catalysis letters 105(3-4), 249-252 (2005). b. Li, Ying; Chen, XiaoChun; Sun, Wei; Liu, Shi Wei; Hou, Wei, “Experimental study of thecatalytic dehydration of ethanol to ethylene on a γ-Al₂O₃ catalyst,”Ziran Kexueban 34(5), 449-452 (2007). c. Hu, Yaochi; Huang, He; Shi,Haifeng; Hu, Yi; Yan, Jie; Chen, Li, “Catalytic dehydration of ethanolto ethylene using transition metal modified HZSM-5,” Huaxue Yu ShengwuGongcheng 24(2), 19-21 (2007). d. Mostafa, M. R., Youssef, A. M.,Hassan, S. M., “Conversion of ethanol and isopropanol on alumina,titania and alumina titania catalysts,” Material Letters 12, 207-213(1991). e. Cursetji, R. M.; Singh, A. N.; Deo, A. V., “Ethylene fromethyl alcohol on high silica zeolite catalyst,” Chemical Age of India37(6), 407-410 (1986). f. Le Van Mao, R., Levesque, P., McLaughlin, G.,Dao, L. H., “Ethylene from ethanol over zeolite catalysts,” AppliedCatalysis 34, 163-179 (1987). g. Huang, X, Hu, Y., Li, H., Huang, H.,Hu, Y., “Study on dehydration of ethanol to ethylene catalyzed byalkaline-earth metal modified HZSM-5,” Huaxue Shiji 29(12), 705-707(2007).

TABLE IV Oligomerization of Alcohols, Carboxylic Acids, or Ketones toHydrocarbons Temperature Pressure Catalyst (° C.) (kPa) ReferenceH-ZSM-5 (Si/Al ratio > 12) 260-540 Atmospheric U.S. Pat. No. to 20,7003,894,106 ZSM-5, ZSM-11, ZSM-12, 260-540 U.S. Pat. No. ZSM-21, TEAMordenite 3,894,107 (Si/Al ratio > 12) H form Alumina, silica-alumina,380-540 U.S. Pat. No. acid activated clay, sodium- 3,928,483 poisonedH-ZSM-5 zeolite, H-ZSM-5 zeolite (Si/Al > 30) ZSM-5, ZSM-11, ZSM-12,290-540 U.S. Pat. No. ZSM-23, ZSM-35, 4,359,595 ZSM-38, ZSM-48 (Si/Alratio > 12), H form Ruthenium supported in 150-350 1,100-5,520 U.S. Pat.No. catalytically active amount 4,513,161 composited with titania ortitania-containing support Silica-alumina, Y zeolite, 300-500Atmospheric U.S. Pat. No. mordenite, binary oxides, to 3,500 5,191,142beta zeolites, zeolite L, MAZ, alumina-expanded bentonite clay, USY,REY, ZSM-5, FER, GME, MTW, erionite and crystalline silicon-aluminumphosphate molecular sieves, crystalline borosilicates Beta zeolite(Si/Al ratio 200-500 a. 12.5, 37.5, 75), mordenite (MOR) (Si/Al ratio45), ultra stable Y (USY) zeolite (Si/Al ratio 30), ferrierite (Si/Alratio 27.5), faujasite H-ZSM-5 zeolite b. Beta, H-ZSM-5, Y zeolites300-400 c. H-ZSM-5 (Si/Al ratio 25) 300-500 130 d. zeolitesHeteropolyacid compounds 300-400 e. of molybdenum and tungsten andammonium 12-tungstophosphate Amorphous silica-alumina 310-450Atmospheric f. (Si/Al ratio 11.3) ZSM-5 zeolite g. Triflic acid (TFA or200-210 h. trifluoromethane sulfonic acid) bearing ZSM-5 zeolite a.Aramendía, M. A., Borau, V., Jiménez, C., Marinas, J. M., Roldán, R.,“Catalytic application of zeolites in methanol conversion tohydrocarbons,” Chemistry Letters 31(7), 672-673 (2002). b. Udrea, I.,Udrea, M., Frunza, L., Angelescu, E., Onu, P., Ginju, D., “Conversion ofC1-C4 alcohols to hydrocarbons over ZSM-5 type zeolites,” HeterogeneousCatalysis 6^(th) (Pt. 2) (1987). c. Hutchins, G. J., Johnston, P., Lee,D. F., Warwick, A., Williams, C. D., Wilkinson, M., “The conversion ofmethanol and other O-compounds to hydrocarbons over zeolite β,” Journalof catalysis 147, 117-185 (1994). d. Setiadi, S., Kojima, T., Tsutsui,T, “Conversion of acetone to aromatic chemicals with HZSM-5,” Journal ofthe Japan Institute of Energy 82(12), 926-932 (2003). e. Hayashi, H.,Moffat, J. B., “Conversion of methanol into hydrocarbons over ammonium12-tungstophosphate,” Journal of Catalysis 83, 192-204 (1983). f.Comelli, R. A., Figoli, N. S., “Transformation of C1-C4 alcohols intohydrocarbons on an amorphous silica-alumina catalyst,” Applied Catalysis36, 299-306 (1988). g. Costa, E.; Aguado, J.; Ovejero, G.; Canizares,P., “Synthesis of hydrocarbons starting from fermentation products,”Revista de la Real Academia de Ciencias Exactas, Fisicas y Naturales deMadrid 79(3), 453-456 (1985). h. Le Van Mao, R., Huang, L., “Thebioacids/bioacetone-to-hydrocarbons (BATH) process,” Chemical Industries46 (novel prod. methods ethylene), 425-442 (1992).

TABLE V Hydrogenation of Ketones Temperature Pressure Catalyst (° C.)(kPa) Reference Raney nickel ~130 ~1,500 a. Zeolites A, X, Y and200-450  3,040 b. mordenite (MOR) in forms of Na, Ca, NH₄, Ce andrare-earth elements (REE) Platinum catalysts 30-90, >90 100 c. (Pt/TiO₂,Pt/η-Al₂O₃, Pt/SiO₂, Pt powder, and Pt/Au) Palladium 100-250 atmospheric c., d. Copper Chromite 20-300 e. Copper oxide-chromium60-200 200-1100 Japan Patent oxide catalyst JP 03041038 Supportedruthenium 75-180 350-6900 U.S. Pat. No. catalyst (support: silica,5,495,055 alumina, carbon, kieselguhr, and calcium carbonate) a. Chang,N., Aldrett, S., Holtzapple, M. T., Davison, R. R., “Kinetic studies ofketone hydrogenation over Raney nickel catalyst,” Chemical EngineeringScience 55(23), 5721-5732 (2000). b. Minachev, Kh. M., Garanin, V. I.,Kharlamov, V. V., Kapustin, M. A., “Hydrogenation of acetone on cationicforms of zeolites,” Russian Chemical Bulletin 23(7), 1472-1475 (1974).c. Sen, B., Vannice, M. A., “Metal-support on acetone hydrogenation overplatinum catalysts” Journal of Catalysis 113, 52-71 (1988). d. vanDruten, G. M. R., Ponec, V, “Promotion effects in the hydrogenation ofpropanal and acetone over palladium,” React. Kinet. Catal. Lett. 68(1),15-23 (1999). e. Yurieva, T. M., “Mechanisms for activation of hydrogenand hydrogenation of acetone to isopropanol and of carbon oxides tomethanol over copper-containing oxide catalysts,” Catalysis Today 51,457-467 (1999).

When referring to particular product streams herein, it should beunderstood that, although the primary product and products aredescribed, other products may exist in the product stream. As onenon-limiting example, described in more detail below, a stream of watermay contain alcohol.

FIGS. 1A and 1B show block diagrams of embodiments of complete biomassconversion with two options depending of what buffering system is chosenfor the fermentation.

FIG. 1A shows a calcium-based system 100A, and FIG. 1B shows anammonia-based system 100B.

According to FIGS. 1A and 1B, pretreatment and fermentation of biomassoccurs at Step 110A/110B. Pretreatment is optional depending on whetherthe biomass is sufficiently digestible “as is.” Pretreatment may beperformed as known in the art, for example, by using lime pretreatmentas described in, but not limited to, U.S. Pat. Nos. 5,693,296 and5,865,898, and U.S. Patent App. Nos. 60/423,288 and 60/985,059. Thedigestible biomass may then be directly fermented to carboxylate salts.Such fermentation to carboxylate salts may be performed, for example, asdescribed in, but not limited to, U.S. Pat. No. 5,962,307 and U.S.patent application Ser. Nos. 11/298,983 and 11/456,653. Depending on thebuffering system utilized, the carboxylate salts produced in embodimentsare calcium or ammonium salts. From the fermentation, a liquidfermentation broth may be obtained, which is mostly water andcarboxylate salts. For further treatment, the carboxylate salts may bedewatered at Step 120A/120B. Dewatering may be performed, for example,using processes or systems described in, but not limited to, U.S. Pat.Nos. 5,986,133, 7,251,944, and 7,328,591, and U.S. Pat. App. No.60/985,059. Teachings of certain embodiments recognize that dewateringmay produce concentrated carboxylate salts. In some embodiments, thewater produced by step 120A/120B may be used as an input at step110A/110B.

In calcium-based system 100A, the calcium carboxylate salts may undergothermal conversion into ketones at step 125A. Systems and processes foreffecting such thermal conversion into ketones are described, forexample, in U.S. Pat. Nos. 6,043,392 and 6,262,313. In addition,carboxylic acids may be recovered from the salts at step 130A. Recoveryof carboxylic acids may be effected via “acid springing,” for example,as described in, but not limited to, U.S. Pat. No. 6,395,926. Theresulting carboxylic acids or ketones may then be sent downstream to beprocessed at step 140A, as described in FIGS. 2-24, 27 and 28.Alternatively or additionally, the formation of ketones using, forexample, thermal conversion as described in FIGS. 1A and 25 (Step 125A)may be integrated with the appropriate downstream processing asdescribed in FIGS. 18-24, using a sweep gas as described in FIG. 26.Ketones/ketone vapors may also be generated by passing carboxylic acidsthrough a catalytic bed of, for example, zirconium oxide.

In the ammonia-based system 100B, the carboxylic acids may be recoveredfrom the ammonium carboxylate salts at step 130B. Recovery of carboxylicacids may be effected via “acid springing,” for example, as describedin, but not limited to, U.S. patent application Ser. No. 11/456,653. Theresulting carboxylic acids may be sent downstream to be processed atstep 140B, as described in FIGS. 2-22, 27 and 28. Alternatively oradditionally, the ammonium carboxylate salts may be sent directlydownstream to be processed as described in FIGS. 29-42.

In both the calcium-based system 100A and the ammonia-based system 100B,hydrogen may be added to step 140A/140B as needed. The hydrogen may begenerated off-site and delivered (e.g., via pipeline or other suitabledevice), or it may be generated on site from gasification of theundigested fermentation residue, from steam reforming of natural gas,from the waste hydrocarbon gases generated in the conversion, or fromother suitable methods. In addition, some hydrogen is produced in thefermentation step 110A/110B that may be recovered in a manner similar asdescribed in, but not limited to, U.S. patent application Ser. No.11/948,506. Teachings of certain embodiments recognize that highly-purehydrogen may not be required.

FIG. 2 shows a block diagram of a system 200 for converting carboxylicacids to alcohols, according to an embodiment. Carboxylic acids 202 areesterified by reacting with olefins 204 in an esterification reactor220. The resulting esters 205 are hydrogenolyzed to alcohols 206 in aseparate hydrogenolysis reactor 222. A portion of alcohol product 206may be dehydrated to form olefins 204 in a dehydration reactor 224; theremaining alcohol 206 may be harvested as product. If desired, thealcohol products 206 exiting the hydrogenolysis reactor 222 can beseparated by distillation. The higher alcohols can be dehydrated to formhigher olefins (propylene and above). Teachings of certain embodimentsrecognize that using olefins instead of primary alcohols may enable theesterification reactor 220 to produce ester without producing water.

FIG. 3 shows a detailed description of system 200 for convertingcarboxylic acids to alcohols, according to an embodiment. In thisembodiment, the carboxylic acid stream 202 is split into two portions202 a and 202 b. Stream 202 a is sent to sensible heat exchanger 240,latent heat exchanger 241, and sensible heat exchanger 242, such thatthe stream 202 a becomes superheated vapor. Stream 202 b is sent tosensible heat exchanger 243, latent heat exchanger 244, and sensibleheat exchanger 245, such that the stream 202 b becomes superheatedvapor. The superheated carboxylic acid vapor streams 202 a and 202 breact with olefins 204 in esterification reactor 220 to form esters 205.In some embodiments, esterification reactor 220 has its own temperaturecontrol system. Esters 205 react with hydrogen in a hydrogenolysisreactor 222 to produce alcohols 206. In some embodiments, hydrogenolysisreactor 222 has its own temperature control system.

Alcohol product stream 206 is split into two streams 206 a and 206 b.Stream 206 a enters expander 246, where the pressure is reduced. Thelow-pressure alcohol enters dehydration reactor 224. Teachings ofcertain embodiments recognize that lowering the pressure in expander 246may improve dehydration performance because dehydration tends to occurat lower pressure. In some embodiments, dehydration reactor 224 has itsown temperature control system. Stream 206 a (comprising olefins 206 aaand water 206 ab) exiting dehydration reactor 224 may then be compressedin compressor 247 and enter sensible heat exchanger 245 and latent heatexchanger 244, which cools the stream and allows water 206 ab tocondense. Olefin 206 aa and water 206 ab may then be separated in tank248. Olefin 206 aa is heated in sensible heat exchanger 245 so it canenter esterification reactor 220 as all or part of the olefin 204. Thewater 206 ab exiting tank 248 is cooled in sensible heat exchanger 243.In some embodiments, water 206 ab may flow through a turbine 249 as partof a high-pressure liquid 206 ab′ to recover expansion energy. Theliquid 206 ab′ has primarily water, but it may also have some alcoholsbecause the dehydration reaction in dehydration reactor 224 isreversible. The alcohols in liquid 206 ab′ are recovered by distillationin column 250 and returned to the alcohol stream 206.

Stream 206 b, which represents the portion of the alcohol that isrecovered as product, is cooled through sensible heat exchanger 242,latent heat exchanger 241, and sensible heat exchanger 240. The gasspace in tank 251 may contain hydrogen, which may be then recycled tohydrogenolysis reactor 222. In some embodiments, the stream 206 b mayflow through a turbine 252 as part of a high-pressure liquid 206 b′ torecover expansion energy. The gas space in tank 253 may containhydrogen, which is compressed using compressor 254. A portion thereofmay be returned via line 206 bb to hydrogenolysis reactor 222.

Recycle stream 206 bb may contain non-hydrogen gases, which may bepurged via line 206 bb′ in certain embodiments to prevent accumulationwithin the system. The purged gases in line 206 bb′ may be sent to aseparator to recover the hydrogen, or they may be burned for processheat. Esterification reactor 220 and/or hydrogenolysis reactor 222 canoperate at a higher pressure (˜2000 to 4000 kPa), whereas dehydrationreactor 224 operates at a lower pressure (˜20 to 500 kPa), according tocertain embodiments. In the illustrated embodiment, expander 246recovers energy from the pressure reduction and allows it to supplementthe energy used by compressor 247.

Certain catalysts, such as zeolites, exhibit both hydrogenation activity(e.g., but not limited to, Minachev, Kh. M., Garanin, V. I., Kharlamov,V. V., Kapustin, M. A., “Hydrogenation of acetone on cationic forms ofzeolites,” Russian Chemical Bulletin 23(7), 1472-1475 (1974)) and theyalso promote the reaction of olefins and carboxylic acids to produceesters (e.g., but not necessarily limited to, U.S. Pat. No. 5,973,193).Therefore, according to teachings of certain embodiments, both thehydrogenation and esterification for making alcohols may be performed inone single reactor. FIG. 4 shows a simplified diagram of system 200 withthe conversion of carboxylic acids to alcohols occurring in one singlereactor 221, according to an embodiment. FIG. 5 shows the detailedsystem 200 described in FIG. 3, but with the esterification reactor 220and hydrogenolysis reactor 222 combined into one single reactor 221.

FIG. 6 shows a block diagram of a system 600 (“Option A”) for convertingcarboxylic acids to hydrocarbons, according to an embodiment. Carboxylicacids 602 react with olefins 604 in an esterification reactor 620 toform esters 605. The esters 605 react with hydrogen in a hydrogenolysisreactor 622 to form alcohol 606. A portion of the alcohol stream 606 issent to the dehydration reactor 624 to produce olefins 604 and water.The remaining portion of the alcohol stream 606 is sent to theoligomerization reactor 626, where it forms hydrocarbons 608 and water.

FIG. 7 shows a detailed description of Option A according to oneembodiment. Carboxylic acid stream 602 is split into two portions, 602 aand 602 b. Stream 602 a is sent to sensible heat exchanger 640, latentheat exchanger 641, and sensible heat exchanger 642, such that thestream 602 a becomes superheated vapor. Stream 602 b is sent to sensibleheat exchanger 643, latent heat exchanger 644, and sensible heatexchanger 645, such that the stream 602 b becomes superheated vapor. Thesuperheated carboxylic acids 602 a and 602 b react with olefins 604 inesterification reactor 620. In some embodiments, esterification reactor620 has its own temperature control system. Esters 605 react withhydrogen in a hydrogenolysis reactor 622 to produce alcohol 606. In someembodiments, hydrogenolysis reactor 622 has its own temperature controlsystem.

Alcohol product stream 606 is split into two streams 606 a and 606 b.Stream 606 a enters expander 646, where the pressure is reduced. Thelow-pressure alcohol enters dehydration reactor 624. In someembodiments, dehydration reactor 624 has its own temperature controlsystem. Stream 606 a exiting dehydration reactor 624 (comprising olefins606 aa and water 606 ab) may then be compressed in compressor 647 andenter sensible heat exchanger 645 and latent heat exchanger 644, whichcools the stream and allows water 606 ab to condense. Olefin 606 aa andthe water 606 ab are separated in tank 648. Olefin 606 aa is heated insensible heat exchanger 645 so it can enter esterification reactor 620as part of the olefin 604. Water 606 ab exiting tank 648 is cooled insensible heat exchanger 643. In some embodiments, the water 606 ab mayflow through a turbine 649 as part of a high-pressure liquid 606 ab′.The liquid 606 ab′ comprises primarily water, but it may also comprisesome alcohol because the dehydration reaction in dehydration reactor 624is reversible. The alcohols in liquid 606 ab′ are recovered bydistillation in column 650 and are returned to the alcohol stream 606.

The stream 606 b is sent to the oligomerization reactor 626. In someembodiments, oligomerization reactor 626 has its own temperature controlsystem. The product exiting oligomerization reactor 626 is cooledthrough sensible heat exchanger 642, latent heat exchanger 641, andsensible heat exchanger 640. Tank 651 may contain unreacted species(e.g., low-molecular-weight olefins), which may be returned via 607 tooligomerization reactor 626. In embodiments, stream 606 b may flowthrough a turbine 652 as part of a high-pressure liquid 606 b′ torecover expansion energy. Tank 653 may contain unreacted species, whichare compressed using compressor 654 and returned via 606 bb tooligomerization reactor 626. Hydrocarbons are removed from tank 653 via608.

Recycle streams 607 and/or 606 bb may contain non-reactive gases, whichmay be purged via line 606 bb′ to prevent accumulation within thesystem. The purged gases may be sent to a separator to recover thereactive components, or they may be burned for process heat.Esterification reactor 620, hydrogenolysis reactor 622, and/oroligomerization reactor 626 can operate at a higher pressure (˜3000kPa), whereas dehydration reactor 624 can operate at a lower pressure(˜20 to 500 kPa), according to certain embodiments. In the illustratedembodiment, expander 646 recovers energy from the pressure reduction andallows it to supplement the energy used by compressor 647.

As with FIGS. 4 and 5, FIGS. 8 and 9 show the same configuration as inFIGS. 6 and 7, but using only one reactor 621 to perform theesterification and hydrogenolysis.

FIG. 10 shows a block diagram of a system 1000 (“Option B”) forconverting carboxylic acids to hydrocarbons, according to anotherembodiment. Carboxylic acids 1002 react with olefins 1004 in anesterification reactor 1020 to form esters 1005. Esters 1005 arehydrogenolyzed to alcohols 1006 in a hydrogenolysis reactor 1022. Thealcohol stream 1006 is sent to an oligomerization reactor 1026. In someembodiments, oligomerization reactor 1026 operates with a residence timethat is short enough to form significant amounts of unreactedintermediates (olefins), which are separated from the final products,hydrocarbons 1008 and water. In the illustrated embodiment, the olefins1004 are fed back to the esterification reactor 1020.

FIG. 11 shows a detailed description of Option B, according to anotherembodiment. Carboxylic acid stream 1002 is sent to sensible heatexchanger 1040, latent heat exchanger 1041, and sensible heat exchanger1042, such that the carboxylic acid stream 1002 becomes superheatedvapor. The superheated carboxylic acids 1002 react with olefins 1004 inthe esterification reactor 1020 to produce esters 1005. In someembodiments, esterification reactor 1020 has its own temperature controlsystem. Esters 1005 are sent to hydrogenolysis reactor 1022 to producealcohols 1006. In some embodiments, hydrogenolysis reactor 1022 has itsown temperature control system.

Alcohol stream 1006 is sent to oligomerization reactor 1026. In someembodiments, oligomerization reactor 1026 has its own temperaturecontrol system. The product exiting the oligomerization reactor iscooled through sensible heat exchanger 1042, latent heat exchanger 1041,and sensible heat exchanger 1040. In some embodiments, the stream 1006may flow through a turbine 1052 as part of a high-pressure liquid 1006′to recover expansion energy. In embodiments, the residence time inoligomerization reactor 1026 is short enough that there is a significantamount of unreacted species (e.g., low-molecular-weight olefins) in thegas space of tank 1051, which may then be supplied to the esterificationreactor 1020. Similarly, tank 1053 may contain unreacted species 1007,which may be compressed using compressor 1054 and sent to esterificationreactor 1020. Hydrocarbons 1008 are removed from tank 1053.

The recycle stream 1007 and/or 1006 bb may contain non-reactive gases,which may be purged 1006 bb′ to prevent accumulation within the system.The purged gases may be sent to a separator to recover the reactivecomponents, or they may be burned for process heat. In certainembodiments, esterification reactor 1020, hydrogenolysis reactor 1022,and oligomerization reactor 1026 can operate at a higher pressure (˜3000kPa).

FIGS. 12 and 13 show the same configurations as in FIGS. 10 and 11 butusing only one single reactor 1021 to perform the esterification andhydrogenolysis.

FIG. 14 shows a block diagram of system 1400 (“Option C”) for convertingcarboxylic acids to hydrocarbons, according to another embodiment.Carboxylic acids 1402 react with olefins 1404 in an esterificationreactor 1420 to form esters 1405. The esters 1405 are hydrogenolyzedinto alcohols 1406 in a hydrogenolysis reactor 1422. The alcohol stream1406 is sent to a dehydration reactor 1424 to produce water and olefins1404. The olefins stream 1404 is split in two portions: one stream goesto the esterification reactor 1420, and the other goes tooligomerization reactor 1426, which produces hydrocarbons 1408 andwater. Because only olefins 1404 are being fed to oligomerizationreactor 1426, no water should be produced during the oligomerization;however, teachings of some embodiments recognize that some alcohol maybe expected in the olefin stream going to oligomerization reactor 1426.In the presence of hydrogen (which remains from the hydrogenolysis) andcarbon monoxide (which can be formed in dehydration reactor 1424),methanol and other alcohols can be formed in oligomerization reactor1426; therefore, water may form.

FIG. 15 shows a detailed description of Option C, according to anotherembodiment. Carboxylic acid stream 1402 is split into two portions, 1402a and 1402 b. Stream 1402 a is sent to sensible heat exchanger 1440,latent heat exchanger 1441, and sensible heat exchanger 1442, such thatstream 1402 a becomes superheated vapor. Stream 1402 b is sent tosensible heat exchanger 1443, latent heat exchanger 1444, and sensibleheat exchanger 1445, such that stream 1402 b becomes superheated vapor.The superheated carboxylic acids 1402 a and 1402 b react with olefins1404 in esterification reactor 1420 to produce esters 1405. Inembodiments, esterification reactor 1420 has its own temperature controlsystem. Esters 1405 are sent to hydrogenolysis reactor 1422 to producealcohols 1406. In embodiments, hydrogenolysis reactor 1422 has its owntemperature control system.

Alcohol product stream 1406 enters expander 1446, where the pressure isreduced. The low-pressure alcohols enter dehydration reactor 1424. Insome embodiments, dehydration reactor 1424 has its own temperaturecontrol system. The stream 1406 (comprising olefins 1406 a and water1406 b) exiting dehydration reactor 1424 is compressed using compressor1447 and enters sensible heat exchanger 1445 and latent heat exchanger1444, which cools the stream 1406 and allows water 1406 b to condense.Olefins 1406 a and water 1406 b are separated in tank 1448. Olefins 1406a are re-heated in sensible heat exchanger 1445. Olefin stream 1406 a issplit into two portions: 1406 aa and 1406 ab. Stream 1406 aa is sent tooligomerization reactor 1426, and stream 1406 ab is sent toesterification reactor 1420. Water 1406 b exiting tank 1448 is cooled insensible heat exchanger 1443. In embodiments, water 1406 b flows througha turbine 1449 as part of a high-pressure liquid 1406 b′. The liquid1406 b′ comprises primarily water, but may also comprise some alcoholbecause the reaction in dehydration reactor 1424 is reversible. Thealcohols in liquid 1406 b′ are recovered by distillation in column 1450and are returned to alcohol stream 1406.

The product exiting oligomerization reactor 1426 is cooled throughsensible heat exchanger 1442, latent heat exchanger 1441, and sensibleheat exchanger 1440. In some embodiments, stream 1406 aa flows through aturbine 1452 as part of a high-pressure liquid 1406 aa′ to recoveryenergy expansion. The gas space in tank 1451 may contain unreactedspecies (e.g., low-molecular-weight olefins), which are returned to theoligomerization reactor 1426. Similarly, tank 1453 may contain unreactedspecies, which are compressed using compressor 1454 and returned tooligomerization reactor 1426.

The recycle stream may contain non-reactive gases, which may be purgedto prevent accumulation within the system. The purged gases may be sentto a separator to recover the reactive components, or they may be burnedfor process heat. Esterification reactor 1420, hydrogenolysis reactor1422, and/or oligomerization reactor 1426 can operate at a higherpressure (˜3000 kPa), whereas the dehydration reactor 1424 operates at alower pressure (˜20 to 500 kPa), according to certain embodiments. Inthe illustrated embodiment, expander 1446 recovers energy from thepressure reduction and allows it to supplement the energy used bycompressor 1447.

FIGS. 16 and 17 show the same configuration as in FIGS. 14 and 15 butusing a single reactor 1421 to perform the esterification andhydrogenolysis.

FIG. 18 shows a block diagram of a system 1800 (“Option A1”) forconverting ketones or carboxylic acids directly to hydrocarbons in theoligomerization reactor, according to another embodiment. The ketones orcarboxylic acids 1802 feed into an oligomerization reactor 1826. Theproducts that exit oligomerization reactor 1826 may be separated in atank 1851 into water, hydrocarbons 1808, and gaseous products. In someembodiments, gaseous product may represent 30-40% of the products thatexit the oligomerization reactor 1826. The gaseous product may be burnedfor process heat or reformed into hydrogen in a reformer 1823 usingstandard technology (e.g., steam reforming, partial oxidation, or othersuitable systems and methods). The hydrogen may be used to convert aportion of the ketones or carboxylic acids 1802 into alcohols 1806 in analcohol reactor 1821; these alcohols 1806 may then be sent to theoligomerization reactor 1826.

If ketones are used as the feed, then hydrogenation may be very directusing appropriate hydrogenation catalyst (e.g., Raney nickel, platinum,copper chromite, or other suitable hydrogenation catalyst). Ifcarboxylic acids are used as the feed, then alcohol production 1821 mayinclude one of the processes described in FIGS. 2 through 5. The detailsof the process may be similar to those described in FIGS. 3, 5, 7, 9,11, 13, 15 and 17, which use appropriate sensible and latent heatexchangers to heat and cool the process streams, as well as compressorsand expanders to manipulate the pressure. These details are notrepeated.

FIG. 19 shows a block diagram of a system 1900 (“Option B1”) forconverting ketones or carboxylic acids directly to hydrocarbons in theoligomerization reactor. This embodiment incorporates a separator 1825(e.g., pressure-swing adsorption, membranes, cryogenic distillation)into Option A1 to recover olefins 1804 from the gaseous stream andreturn them to oligomerization reactor 1826 rather than sending them toreformer 1823.

FIG. 20 shows a block diagram of a system 2000 (“Option A2”) forconverting ketones or carboxylic acids directly to hydrocarbons. Thisembodiment modifies Option A1 by incorporating the alcohol production(e.g., hydrogenation) and oligomerization mechanisms into a singlereactor 1827. Teachings of certain embodiments recognize that, becausethe same catalysts employed for oligomerization are known to effecthydrogenation as well (e.g., U.S. Pat. No. 3,894,107 and Minachev, Kh.M., Garanin, V. I., Kharlamov, V. V., Kapustin, M. A., “Hydrogenation ofacetone on cationic forms of zeolites,” Russian Chemical Bulletin 23(7),1472-1475 (1974)), the ketones or the carboxylic acids and hydrogen maybe fed directly to the same reactor, thus avoiding having a separatehydrogenation reactor and other equipment needed for alcohol generation.

FIG. 21 shows a block diagram of a system 2100 (“Option B2”) forconverting ketones or carboxylic acids directly to hydrocarbons. Thisembodiment modifies Option B1 by incorporating the alcohol production(e.g., hydrogenation) and oligomerization mechanisms into a singlereactor 1827. Teachings of certain embodiments recognize that, becausethe same catalysts employed for oligomerization are known to effecthydrogenation as well, the ketones or the carboxylic acids and hydrogenmay be fed directly to the same reactor, thus avoiding having a separatehydrogenation reactor and other equipment needed for alcohol generation.

FIG. 22 shows a detailed process flow diagram of a system 2200 for thedirect conversion of carboxylic acids or ketones to hydrocarbons using asingle reactor for both hydrogenation and oligomerization (based onOption A2 of FIG. 20 and Option B2 of FIG. 21) according to oneembodiment. The carboxylic acid or ketone stream 2202 is sent (e.g., viafeed pump 2203) to sensible heat exchanger 2240, latent heat exchanger2241, and sensible heat exchanger 2242, such that the stream 2202becomes superheated vapor. The superheated carboxylic acids or ketonesand hydrogen are sent to the hydrogenation/oligomerization reactor 2227.In some embodiments, hydrogenation/oligomerization reactor 2227 has itsown temperature control system. The product exitinghydrogenation/oligomerization reactor 2227 is cooled through sensibleheat exchanger 2242, latent heat exchanger 2241, and sensible heatexchanger 2240. In some embodiments, this high pressure liquid flowsthrough a turbine 2252 as part of a high-pressure liquid 2202′ torecover expansion energy. There may be unreacted species (e.g.,low-molecular-weight olefins) in the gas space of tank 2251, which maybe recycled to hydrogenation/oligomerization reactor 2227. Similarly,tank 2253 may contain unreacted species, which may be compressed usingcompressor 2254 and sent back to the hydrogenation/oligomerizationreactor 2227. Hydrocarbons 2208 may be removed from tank 2253.

The recycle stream may contain non-reactive gases, which may be purgedto prevent accumulation within the system. The purged gases may be sentto a separator to recover the reactive components, or they may be burnedfor process heat or reformed into hydrogen.Hydrogenation/oligomerization reactor 2227 may operate at a higherpressure (˜3000 kPa), according to certain embodiments.

FIG. 23 shows a block diagram for an embodiment of a system 2300 thatdirectly converts ketones to hydrocarbons, which corresponds to one ofthe routes shown in FIG. 1A. In the illustrated embodiment, biomass 2370is optionally pretreated 2380 to enhance biodegradability using lime(e.g., using, but not limited to, lime pretreatment described in, butnot limited to, U.S. Pat. Nos. 5,693,296 and 5,865,898, and U.S. Pat.App. Nos. 60/423,288 and 60/985,059). Then, the pretreated biomass 2370is directly fermented in the fermenter 2382, creating carboxylate salts2372 (e.g., as described in, but not limited to, U.S. Pat. No. 5,962,307and U.S. patent application Ser. Nos. 11/298,983 and 11/456,653). Theresulting carboxylate salts 2372 are dewatered and, as a result,concentrated (e.g., using processes or systems described in, but notlimited to, U.S. Pat. Nos. 5,986,133, 7,251,944, and 7,328,591 and U.S.Pat. App. No. 60/985,059) in a concentrator 2384. The concentrated saltsare converted to ketones 2302 (e.g., using processes or systemsdescribed in, but not limited to, U.S. Pat. Nos. 6,043,392 and6,262,313) at ketone reactor 2386. Ketones 2302 may be directlyconverted to hydrocarbons 2308 and alcohols 2306 in a manner similar tothe processes described in FIGS. 18-22. However, in the illustratedembodiment, the gases 2329 from oligomerization reactor 2326 aredirected to the fermenter 2382, for example, through tank 2351. In thefermenter 2382, biologically reactive species (e.g., hydrogen and carbonmonoxide) are converted to carboxylate salts 2372. Carbon dioxide isremoved from the energetic gases (e.g., hydrogen, methane) 2330′ exitingfermenter 2382 in fermenter exit gas 2330 via a separator 2325 usingstandard methods (e.g., amine adsorption, membranes, cryogenics).Energetic gases 2330′ are sent to a reformer 2323 to produce hydrogenfor alcohol reactor 2321. All or a portion (2310) of the water 2331 thatexits oligomerization reactor 2326 may be used in the reformer 2323, forexample after separation in tank 2351.

FIG. 24 shows a block diagram of a system 2400 that directly convertsketones to hydrocarbons, which corresponds to one of the routes shown inFIG. 1A, according to one embodiment. This embodiment modifies system2300 by incorporating the alcohol production (e.g., hydrogenation) andoligomerization mechanisms into a single reactor 2327, with both theketones and the hydrogen fed to this reactor.

As mentioned and indicated in FIG. 1, in embodiments, biomass may beconverted to hydrocarbons using a calcium-based system. Via thisprocess, ketone production from carboxylate salts is integrated withsubsequent conversion of the ketones into alcohols and hydrocarbons.FIG. 25, a subset of FIG. 1, is a block diagram showing complete biomassconversion for calcium-based systems, according to an embodiment. Thefirst step in the process is pretreatment (e.g., but not limited to,lime pretreatment). Such lime pretreatment is described, for example,but not limited to, in U.S. Pat. Nos. 5,693,296 and 5,865,898 as well asin U.S. Pat. App. Nos. 60/423,288 and 60/985,059. Such pretreatment isoptional if the raw biomass is sufficiently digestible. The digestiblebiomass is then directly fermented to carboxylate salts. Suchfermentation may be performed as described, for example, but not limitedto, in U.S. Pat. No. 5,962,307 and U.S. patent application Ser. Nos.11/298,983 and 11/456,653. From the fermentation, a liquid fermentationbroth is obtained, which comprises mostly water and the carboxylatesalts. For further treatment, the carboxylate salts may be concentrated,for example, but not limited to, via dewatering 120A as described inU.S. Pat. Nos. 5,986,133, 7,251,944 and 7,328,591 and U.S. Pat. App. No.60/985,059. In the case currently being considered, where calciumcarboxylate salts have been created, such calcium carboxylate salts maybe thermally converted 125A into ketones. Such thermal conversion may beperformed, for example, but not limited to, as described in U.S. Pat.No. 6,262,313. Ketones may also be generated by passing carboxylic acidsthrough a catalytic bed of, for example, zirconium oxide. The resultingketones may be sent downstream to be processed as described hereinabovewith respect to FIGS. 18-24. Thus, in such embodiments, appropriatedownstream processing 140A′ may be performed as described in FIGS.18-24.

Ketones produced in a ketone reactor by the dry distillation ofcarboxylate salts must be removed and cooled down quickly to avoiddegradation. Prior art methods utilize a vacuum to reduce residence timein the ketone reactor, requiring vacuum and chilling equipment. Forexample, in U.S. Pat. No. 6,262,313, carboxylate salts are thermallyconverted to ketones, by heating under vacuum and subsequentcondensation and recovery. As mentioned, the vacuum and condensationhelp increase yields by quickly removing ketones from the hot reactionzone, thus avoiding degradation, however, avoidance of such vacuumconditions may be more economically desirable.

This same goal to avoid ketone degradation can be accomplished by usinga sweep gas, which eliminates the capital associated with maintaining avacuum and oversizing chillers. In embodiments, a ketone reactor isintegrated with downstream unit operations for producing alcohols andhydrocarbons (e.g., as described in FIGS. 18-24) utilizing a sweep gas.FIG. 26 is a block diagram showing a system 100A″ incorporating the useof sweep gas and the direct introduction of ketone vapors from theketone reactor to downstream unit operations, according to anembodiment;

As shown in FIG. 26, costly vacuum and oversized chillers can be avoidedby introducing a sweep gas 121. In this embodiment, calcium carboxylatesalts 124 are introduced into ketone reactor 125B along with sweep gas121. Condensing ketones may be avoided if the hot ketone vapors 126Aexiting ketone reactor 125B are cooled, for example via heat exchanger127A to avoid degradation and cooled ketone vapors 126B are sent to thenext unit operation 140′, as described in FIGS. 18-24 hereinabove. Inthis manner, ketones produced from dry distillation of carboxylate saltsmay be directly sent to alcohol or gasoline conversion without the needfor condensation, thus saving capital on the downstream condensation,heating, and vaporization equipment. Because sweep gas rapidly removesketones formed in ketone reactor 125B, substantial capital savings areexpected by eliminating vacuum and chilling equipment needed to removeand condense low-pressure ketones, which were required by the previousvacuum schemes.

It should be noted that the use of the sweep gas and the directintroduction of the ketone vapors from the ketone reactor to the unitoperations downstream can be used together or may be employedindependently. When the ketone vapors from ketone reactor 125B are sentdirectly to downstream conversion 140′, with or without the aid from asweep gas, the feed pump 2203, sensible heat exchanger 2240, and latentheat exchanger 2241 shown in FIG. 22 may no longer be utilized orneeded. Because ketone vapors from ketone reactor 125B directly react indownstream unit operations 140′, substantial capital saving may berealized by eliminating the condensing equipment, peripherals, anddownstream equipment needed to re-vaporize ketones, which were requiredby prior art vacuum processes. Reacting ketone vapors directly intohydrocarbon or alcohols may also reduce material losses typical whenseparate unit operations are employed, such as condensing. In addition,avoiding liquid heating or cooling may allow for higher energyefficiencies.

Other than oxidants (e.g., oxygen), many gases may be employed as sweepgas. If the sweep gas option is practiced and it is desired to condensethe ketones, a condensing sweep gas can be employed, to minimize/avoidthe loss of ketones vapors that may occur with a non-condensing sweepgas, such as nitrogen. An example of such a condensing sweep gas issteam. Simulations with HYSYS suggest that virtually no ketones are lostwhen steam is used as the sweep gas. Steam has the added advantage that,when hydrocarbons are the final product, when the steam condenses, it isimmiscible with hydrocarbons and is easily separated therefrom.

As mentioned, the sweep gas may be any gas other than oxidants (e.g.,oxygen), but the use of hydrogen may be desired in instances wherehydrogen is used downstream to hydrogenate some or all the ketones.Thus, when producing alcohols or hydrocarbons, hydrogen is a desirablesweep gas because it is also a reactant. To maintain a low partialpressure of ketones in the ketone reactor 125B, it may be desirable torecycle substantial quantities of hydrogen. In such embodiments, gas 122from downstream processing 140A′ may be recycled to ketone reactor 125B.The recycle gas 122 may be passed through countercurrent heat exchanger127B for recycle to ketone reactor 125B.

The literature describes the use of nitrogen sweep gas (Ardagh, E. G.R., Barbour, A. D., McClellan, G. E., and McBride, E. W. (1924).Distillation of acetate of lime, Industrial and Engineering Chemistry,16, 1133-1139). However, nitrogen is both inert and noncondensable.According to this disclosure, a reactive (e.g., hydrogen) or condensable(e.g., steam) sweep gas is utilized.

When sweep gas is employed, an important consideration is whetherhydrocarbon conversion occurs at the same pressure as the ketonereactor, i.e., pressures from vacuum to 1 atm. Experiments have shownthat hydrocarbon conversion of ketones and secondary alcohols overH-ZSM-5 zeolite is feasible at 1 atm. In such case, vapors are sentdirectly to the downstream unit operation after sufficient cooling andheating. If, however, the pressure desired in downstream processing140A′ is higher, a compressor 128 may be used. If sweep gas is beingrecycled, an expander 129 and/or a countercurrent heat exchanger 127Bmay be used, for example, to improve energy efficiency.

If the pressure and temperature of the ketone conversion and hydrocarbonconversion reactions are similar, a simpler method may be implemented.In this case, the catalyst can be placed in the exhaust ports of ketonereactor 125B so that the ketones react when exiting ketone reactor 125B.

In some of these embodiments and some downstream unit operations forconverting ketones into hydrocarbons, a dual-catalyst bed can beemployed, where a hydrogenation catalyst (e.g., copper chromite) isloaded in the first part of the reactor, followed by thedehydration/oligomerization catalyst (e.g., H-ZSM-5 zeolite). Thisdual-catalyst bed may serve to allow conversion of all or most of theketones to alcohols, thus increasing yields and allowing for productionof more desirable hydrocarbons. A dual-catalyst bed can thus be employedwhere a hydrogenation catalyst is first used that converts all or partof the ketones to alcohols, and is followed by adehydration/oligomerization catalyst that converts the alcohols and/orketones to hydrocarbons. Alternatively, a zeolite catalyst can bemodified to incorporate hydrogenation catalyst (e.g., platinum) directlyin its pores. Employing two different catalysts in the same bed mayreduce capital equipment costs and, by combining two reactions into onereactor, may also minimize material losses.

In many cases, the hydrocarbon products exiting the oligomerizationreactor contain significant quantities of olefins. In embodiments, thesecondensed products, which are substantially free of water, are sent toanother oligomerization reactor (or recycled to the oligomerizationreactor) thereby increasing the chain length of the final hydrocarbonproduct.

FIG. 27 shows a block diagram of a system 2500 that directly convertscarboxylic acids to hydrocarbons, which corresponds to one of the routesshown in FIGS. 1A and 1B, according to one embodiment. This embodimentmodifies system 2300 of FIG. 23 by converting carboxylic acids 2302(instead of ketones) directly into hydrocarbons 2308. The process stepsare similar to those described in system 2300, except that thecarboxylate salts are converted to carboxylic acids (e.g., via “acidspringing,” described in, but not limited to, U.S. Pat. No. 6,395,926 orU.S. patent application Ser. No. 11/456,653) using an acid recoverysystem 2388.

FIG. 28 shows a block diagram of a system 2600 that directly convertscarboxylic acids to hydrocarbons, which corresponds to one of the routesshown in FIGS. 1A and 1B, according to one embodiment. This embodimentmodifies system 2500 of FIG. 27 by incorporating the alcohol production(e.g., hydrogenation) and oligomerization mechanisms into a singlereactor 2327, with both the carboxylic acids and the hydrogen being fedto this reactor.

FIG. 29 shows a block diagram of a system 2700 for direct conversion ofammonium carboxylate salts to hydrocarbons according to an embodiment.The embodiment modifies Option A1 of FIG. 18 by feeding ammoniumcarboxylate salts 2702 (solids, as a slurry and/or in solution) to thesystem 2700. Ammonium carboxylate salts 2702 are volatile salts, whichwhen completely vaporized are decomposed into ammonia and carboxylicacids. Some other products, such as amides, might also form. In FIG. 29,a portion of the ammonium carboxylate salts 2702 may be sent to analcohol reactor 2721, which converts the ammonium carboxylate salts 2702into alcohols 2706. Teachings of certain embodiments recognize thatconverting some of the ammonium carboxylate salts 2702 may allow thesystem 2700 to take advantage of available hydrogen from reformer 2723.Such conversion to alcohols can be done, for example, by using theprocess described in, but not limited to, U.S. patent application Ser.No. 11/456,653; in another embodiment, they may be converted tocarboxylic acids first (e.g., as described in, but not limited to,patent application Ser. No. 11/456,653) and then converted to alcohols(e.g., as described in FIGS. 2-5). The details of the process aresimilar to those described in FIGS. 3, 5, 7, 9, 11, 13, 15 and 17, whichused appropriate sensible and latent heat exchangers to heat and coolthe process streams, as well as compressors and expanders to manipulatethe pressure. These details are not repeated.

After the ammonium carboxylate salts are vaporized and enteroligomerization reactor 2726, only the carboxylic acid is converted intohydrocarbons 2708. The ammonia 2709 passes unreacted. Such observationwas seen by Butter et al. (U.S. Pat. No. 3,894,107), who passednitrogen-containing compounds through an H-ZSM-5 zeolite catalyst andobtained hydrocarbons and unreacted ammonia as products. Under certainconditions, such as those demonstrated in some of the examplesaccompanying FIGS. 43-50, ammonia may react to form other valuablecompounds, such as acetonitrile.

In system 2700, ammonia 2709 is to be recovered from the products.First, some of the ammonia 2709 will go into solution in the watergenerated; therefore, a separator 2756 (e.g., a flash tank) may beemployed to separate the water 2710 from ammonia 2709. In addition, someammonia may end up in the gases that exit oligomerization reactor 2726.To remove the ammonia from the gas stream, an ammonia separator 2755 maybe employed. For example, a bed packed with solid acid absorbent thatwill bind the ammonia reversibly, followed by desorption of the ammoniaonce the bed is saturated (by having two or more of these unitsoperating in parallel, the process can swing from the absorption cycleto the desorption cycle thus continuously removing the ammonia from thestream). The ammonia-free gases 2757 can then be sent to be burned forprocess heat and/or they may be sent to the reformer 2723 to producehydrogen, as shown in FIG. 29. The hydrogen produced may be employed inthe alcohol reactor 2721. In embodiments, ammonia 2709 is also releasedand recovered in alcohol production unit 2721.

FIG. 30 shows a block diagram of a system 2800 for converting ammoniumcarboxylate salts directly to hydrocarbons in the oligomerizationreactor. The embodiment modifies Option B1 of FIG. 19 by feedingammonium carboxylate salts 2802 to the system 2800, as well asincorporates a separator 2825 (e.g., pressure-swing adsorption,membranes, cryogenic distillation) into the system 2700 of FIG. 29 torecover olefins 2804 from the gaseous stream and return them tooligomerization reactor 2826 rather than sending them to reformer 2823.

FIG. 31 shows a block diagram of a system 2900 for converting ammoniumcarboxylate salts directly to hydrocarbons. The embodiment modifiesOption A2 of FIG. 20 by feeding ammonium carboxylate salts 2902 tosystem 2900, as well as incorporates the oligomerization andhydrogenation processes of system 2700 into a single reactor 2927.Teachings of certain embodiments recognize that, because the samecatalysts employed for oligomerization are known to effect hydrogenationas well (e.g., U.S. Pat. No. 3,894,107, Minachev, Kh. M., Garanin, V.I., Kharlamov, V. V., Kapustin, M. A., “Hydrogenation of acetone oncationic forms of zeolites,” Russian Chemical Bulletin 23(7), 1472-1475(1974), ammonium carboxylate salts and hydrogen may be fed directly tothe same reactor, thus avoiding the need for a separate hydrogenationreactor and other equipment used for alcohol generation.

FIG. 32 shows a block diagram of a system 3000 for converting ammoniumcarboxylate salts directly to hydrocarbons. The embodiment modifiesOption B2 of FIG. 21 by feeding ammonium carboxylate salts 3002 tosystem 3000, as well as incorporates the oligomerization andhydrogenation processes of system 2800 into a single reactor 3027.Teachings of certain embodiments recognize that, because the samecatalysts employed for oligomerization are known to effect hydrogenationas well, the carboxylate salts and hydrogen may be fed directly to thesame reactor, thus avoiding the need for a separate hydrogenationreactor and other equipment used for alcohol generation.

FIG. 33 shows a detailed process flow diagram of a system 3100 for thedirect conversion of ammonium carboxylate salts (solid, as a slurryand/or in solution) to hydrocarbons using a single reactor for bothhydrogenation and oligomerization (based on Options A2 and B2illustrated in FIGS. 31 and 32) according to one embodiment. Theammonium carboxylate stream 3102 is sent to sensible heat exchanger3140, latent heat exchanger 3141, and sensible heat exchanger 3142, suchthat that the stream 3102 becomes superheated vapor. This superheatedstream and hydrogen are sent to hydrogenation/oligomerization reactor3127. In some embodiments, hydrogenation/oligomerization reactor 3127has its own temperature control system. The product exitinghydrogenation/oligomerization reactor 3127 is cooled through sensibleheat exchanger 3142, latent heat exchanger 3141, and sensible heatexchanger 3140. In some embodiments, this high pressure liquid flowsthrough a turbine 3152 as part of a high-pressure liquid 3102′ torecover expansion energy. There may be unreacted species (e.g.,low-molecular-weight olefins) in the gas space of tank 3151, which maybe then recycled to hydrogenation/oligomerization reactor 3127.Similarly, tank 3153 may contain unreacted species, which may becompressed using compressor 3154 and sent back tohydrogenation/oligomerization reactor 3127.

The recycle stream may contain non-reactive gases, which may be purgedto prevent accumulation within the system. The purged gases may be sentto a separator to recover the reactive components, or they may be burnedfor process heat or reformed into hydrogen.Hydrogenation/oligomerization reactor 3127 can operate at a higherpressure (˜3000 kPa), according to certain embodiments.

Before the gas stream from tanks 3151 and 3153 is returned tohydrogenation/oligomerization reactor 3127, or before some of it ispurged, ammonia 3109 may be removed therefrom by passing it through anammonia separator 3155. For example, a bed packed with solid acidabsorbent that will reversibly bind the ammonia may be employed,followed by desorption of the ammonia once the bed is saturated; in someembodiments, by having two or more of these units operating in parallel,the process can swing from the absorption cycle to the desorption cycle,thus continuously removing the ammonia from the stream. In addition, thewater 3110 that is separated from the hydrocarbon 3108 and gas stream intank 3153 may contain some ammonia, which is separated from the water,for example, by increasing its temperature using steam in sensible heatexchanger 3157 and then sending the stream to tank 3156 (e.g., flashtank), allowing ammonia 3109 to be recovered in the vapor phase, whileammonia-free water is recovered in the liquid phase. Alternatively, asteam stripper can also be used to strip the ammonia from the water.

FIG. 34 shows a block diagram of an embodiment of a system 3200 for aprocess that directly converts ammonium carboxylate salts tohydrocarbons, which corresponds to one of the routes shown in FIG. 1B.In the illustrated embodiment, the biomass 3270 is optionally pretreatedat 3280 to enhance biodegradability (e.g., using, but not limited to,lime pretreatment described in, but not limited to, U.S. Pat. Nos.5,693,296 and 5,865,898, and U.S. Pat. App. Nos. 60/423,288 and60/985,059). Subsequently, the pretreated biomass 3270 is directlyfermented at 3282 to ammonium carboxylate salts 3202 (e.g., as describedin, but not limited to, U.S. patent application Ser. Nos. 11/298,983 and11/456,653). The resulting ammonium carboxylate salts 3202 are dewateredat a dewatering unit 3284. As a result, the carboxylate salts 3202 areconcentrated (e.g., using processes or systems described in, but notlimited to, U.S. Pat. Nos. 5,986,133, 7,251,944, and 7,328,591 and U.S.Pat. App. No. 60/985,059). The ammonium carboxylate salts 3202 may bedirectly converted to hydrocarbons 3208 and alcohols 3206, in a mannersimilar to the processes described in FIGS. 29-33. However, in thisembodiment, the gases 3229 exiting oligomerization reactor 3226 aredirected to the fermenter 3282, after separation from hydrocarbons 3208and water 3231 in tank 3251. In fermenter 3282, biologically reactivespecies (e.g., hydrogen and carbon monoxide) and buffering species(e.g., the ammonia) are converted to ammonium carboxylate salts 3202.Energetic gases 3230′ (e.g., hydrogen and/or methane) exiting fermenter3282 are separated from carbon dioxide in fermenter exit gas 3230 usingstandard methods (e.g., amine adsorption, membranes, cryogenics).Energetic gases 3230′ are sent to a reformer 3223 to produce hydrogenfor alcohol producer 3221. Ammonia 3209 recovered from the water exitingthe oligomerization reaction 3226 (e.g., using a tank 3256) and fromalcohol producer 3221 is sent back to the fermenter 3282, via a packedbed 3258 wherein it is contacted with carbon dioxide from separator3225. This produces ammonium bicarbonate, which allows easier pH controlin fermenter 3282. Shown in dotted lines, it might be desired to removethe ammonia present in the gas stream 3229 that is generated from theoligomerization reactor 3226 (e.g., to allow better pH control in thefermentation); thus, an ammonia separator 3255 (e.g., beds packed with asolid acid absorbent) may be employed. The ammonia 3209′ recovered fromthis gas joins the ammonia 3209 from the water 3231 that exitsoligomerization reactor 3255 and the ammonia 3209″ from alcohol reactor3221 and is sent to packed bed 3258′ to be converted into ammoniumbicarbonate to control the pH in the fermentation. Water 3210 that exitsoligomerization reactor 3226 may be used in reformer 3223 after ammonia3209 has been removed therefrom.

FIG. 35 shows a system 3300 that directly converts ammonium carboxylatesalts to hydrocarbons, which corresponds to one of the routes shown inFIG. 1B, according to one embodiment. This embodiment modifies system3200 by incorporating the alcohol production (e.g., hydrogenation) andoligomerization mechanisms into a single reactor 3327, with both theammonium carboxylate salts and the hydrogen being fed to this reactor.

FIGS. 36 through 42 show systems 3400-4000 for direct conversion ofammonium carboxylate salts to hydrocarbons according to severalembodiments. Systems 3400-4000 modify the systems 2700-3300 of FIGS.29-35 by removing and recovering the ammonia from the ammoniumcarboxylate stream prior to entering the oligomerization unit. To removethe ammonia from the gas stream, an ammonia separator3455/3555/3655/3755/3855/3955/4055 may be employed. For example, a bedpacked with solid-acid absorbent may be used to bind the ammoniareversibly. Then, once the bed is saturated, the ammonia is desorbed. Insome embodiments, by having two or more of these units operating inparallel, the process can swing from the absorption to the desorptioncycle, thus continuously removing the ammonia from the stream.

Esterification, hydrogenolysis, and oligomerization reactions areexothermic; therefore, it is possible that some trim cooling might beutilized in some or all of the above configurations. In all cases, in agiven reactor, it is possible that the reaction will be incomplete orthat byproducts will be produced. In these cases, unreacted reactant orbyproducts can be separated and further processed.

Features.

Certain embodiments may include, some, none, or all of the followingfeatures. The reaction of an olefin with a carboxylic acid to form anester is irreversible, so the reaction goes to high conversions easily.In contrast, the reaction of a carboxylic acid with an alcohol to forman ester (the more standard technology) is reversible. It requires thatthe ester products be removed during the reaction to drive the reactionto completion, which is difficult.

The alcohol dehydration reaction is reversible, but it is made morefavorable by operating at low pressures. Pressure reduction isaccomplished with an expander, which recovers energy for use during therecompression of the gases exiting the dehydration reactor.

The capability of the esterification catalyst to also hydrogenolyze theesters formed from the reaction of the olefin and carboxylic acidsavoids expenditures for the implementation of a separate unit forhydrogenolysis, as the carboxylic acids, the olefin and the hydrogen maybe fed directly into the same reactor to produce alcohols.

The direct conversion of ketones or carboxylic acids or ammoniumcarboxylate salts to hydrocarbons (FIGS. 18-24 and 27-35) reduceshydrogen requirements compared to the conversion of ketones, carboxylicacids or ammonium carboxylate salts to alcohols first and then tohydrocarbons (FIGS. 6-17). Combining both of these steps together(direct ketone/carboxylic acid/ammonium carboxylate conversion plusalcohol conversion) allows the process to be “tuned” to match theavailability of hydrogen. If hydrogen is readily available, then thealcohol route is favored. If hydrogen is scarce, then the directketone/carboxylic acid/ammonium carboxylate route is favored.

The capability of oligomerization catalysts to also hydrogenate the feedavoids expenditures for the implementation of a separate unit forproducing alcohols, as the ketones, carboxylic acids and/or the ammoniumcarboxylate salts may be fed directly with the available hydrogen intothe same reactor to produce hydrocarbons.

The processes that integrate with the fermentation (FIGS. 24 and 27-28and FIGS. 34-35) reduce loads on separators and reformers becausebiologically reactive gases and ammonia are converted to carboxylatesalts and do not have to be separated prior to being sent to thereformer or converted to hydrogen in the reformer.

EXAMPLES

The following section provides further details regarding examples ofvarious embodiments.

Example 1 Isopropanol to Hydrocarbons (Si/Al 30)

Materials and Methods:

Liquid isopropanol was vaporized and added to the reactor operated usingthe conditions shown in Table 1.1. The product exiting the reactor wasseparated into two fractions: liquid and gas. The total mass of eachproduct was measured and the composition was determined by gaschromatography/mass spectroscopy (GC/MS).

Results:

Table 1.2 shows the product distribution. Of the total product, theliquid fraction (gasoline) was 68.89% and the gases were 31.13%. Table1.3 shows the classes of products in the liquid fraction.

TABLE 1.1 Example 1 Reaction Conditions- Isopropanol-to-HydrocarbonReactor Isopropanol Flow Rate 10 mL liquid/h Catalyst Mass 6 g WeightHourly Space Velocity (WHSV) 1.31 g reactant/(g catalyst · h)Temperature (Max.) 325° C. Pressure 1 atm (abs) Catalyst H-ZSM-5 (Si/Al30)

TABLE 1.2 Product Distribution (wt %) Gas Liquid CH₄ 0.00% C5s 13.45%CO₂ 0.03% C6s 11.28% C₂H₄ 0.52% C7s 8.99% C₂H₆ 0.03% C8s 18.43% C₃H₆1.10% C9s 10.64% C₃H₈ 7.13% C10s 3.95% CO 0.00% C11+ 2.13% C4s 22.33%Total 68.87% Total 31.13%

TABLE 1.3 Hydrocarbon Distribution in the Liquid (Gasoline) Fraction (wt%) Isomeric Naphthene Paraffins Olefins Compounds Naphthenes OlefinicsAromatics 4.502 4.601 17.872 27.679 3.91 39.234

Example 2 Isopropanol to Hydrocarbons (Si/Al 280)

Materials and Methods:

Liquid isopropanol was vaporized and added to the reactor operated usingthe conditions shown in Table 2.1. The product exiting the reactor wasseparated into two fractions: liquid and gas. The total mass of eachproduct was measured and the composition was determined by gaschromatography/mass spectroscopy (GC/MS).

Results:

Table 2.2 shows the product distribution. Of the total product, theliquid fraction (gasoline) was 63.23% and the gases were 36.77%. Table2.3 shows the classes of products in the liquid fraction. Tables 1.3 and2.3 report identical conditions, except for the catalyst (H-ZSM-5 Si/Al280 versus Si/Al 30). The product distribution is similar; however,Si/Al 280 has less coking and more paraffins in the product, which isimportant for a good fuel. FIG. 43 illustrates the liquid-phase productdistribution as a function of hydrocarbon type and number of carbons forisopropanol oligomerization over H-ZSM-5 zeolite (Si/Al ratio 280).

TABLE 2.1 Example 2 Reaction Conditions- Isopropanol-to-HydrocarbonReactor Isopropanol Flow Rate 10 mL liquid/h Catalyst Mass 6 g WeightHourly Space Velocity (WHSV) 1.31 g reactant/(g catalyst · h)Temperature (Max.) 330° C. Pressure 1 atm (abs) Catalyst H-ZSM-5 (Si/Al280)

TABLE 2.2 Product Distribution (wt %) Gas Liquid CH₄ 0.00% C5s 13.17%CO₂ 0.00% C6s 16.01% C₂H₄ 1.09% C7s 6.98% C₂H₆ 0.00% C8s 14.95% C₃H₆3.13% C9s 6.36% C₃H₈ 6.50% C10s 4.46% CO 0.33% C11+ 1.30% C4s 25.72%Total 63.23% Total 36.77%

TABLE 2.3 Hydrocarbon Distribution in the Liquid (Gasoline) Fraction (wt%) Isomeric Naphthene Paraffins Olefins Compounds Naphthenes OlefinicsAromatics 7.869 4.661 15.215 15.037 1.472 49.349

Example 3 Acetone to Hydrocarbons (Si/Al 30)

Materials and Methods:

Liquid acetone was vaporized and added to the reactor operated using theconditions shown in Table 3.1. The product exiting the reactor wasseparated into two fractions: liquid and gas. The total mass of eachproduct was measured and the composition was determined by gaschromatography/mass spectroscopy (GC/MS).

Results:

Table 3.2 shows the product distribution. Of the total product, theliquid fraction (gasoline) was 67.16% and the gases were 32.86%. Table3.3 shows the classes of products in the liquid fraction. FIG. 44illustrates the liquid-phase product distribution as a function ofhydrocarbon type and number of carbons for acetone oligomerization overH-ZSM-5 zeolite (Si/Al ratio 30). Under these conditions, the reactiondid not quite go to completion; however, other conditions have shownnear-complete conversion is possible (see Example 5).

TABLE 3.1 Example 3 Reaction Conditions- Acetone-to-Hydrocarbon ReactorAcetone Flow Rate 10 mL liquid/h Catalyst Mass 6 g Weight Hourly SpaceVelocity (WHSV) 1.31 g reactant/(g catalyst · h) Pressure 1 atm (abs)Temperature (Max.) 330° C. Catalyst H-ZSM-5 (Si/Al 30)

TABLE 3.2 Product Distribution (wt %) Gas Liquid CH₄ 0.22% C5s 0.92% CO₂1.62% Acetone 8.06% C₂H₄ 2.76% C6s 8.58% C₂H₆ 0.04% C7s 6.52% C₃H₆ 1.19%C8s 18.13% C₃H₈ 1.40% C9s 14.01% CO 0.43% C10s 6.41% C4s 25.20% C11+4.53% Total 32.86% Total 67.16%

TABLE 3.3 Hydrocarbon Distribution in the Liquid (Gasoline) Fraction (wt%) Isomeric Naphthene Paraffins Oxygenates Olefins compounds NaphthenesOlefinics Aromatics Unknown 0 9.351 9.428 2.971 1.88 4.769 54.912 5.033

Example 4 Acetone to Hydrocarbons (Si/Al 280)

Materials and Methods:

Liquid acetone was vaporized and added to the reactor operated using theconditions shown in Table 4.1. The product exiting the reactor wasseparated into two fractions: liquid and gas. The total mass of eachproduct was measured and the composition was determined by gaschromatography/mass spectroscopy (GC/MS).

Results:

Table 4.2 shows the product distribution. Of the total product, theliquid fraction (gasoline) was 74.03% and the gases were 25.97%. Table4.3 shows the classes of products in the liquid fraction. Tables 3.3 and4.3 report identical conditions, except for the catalyst. The Si/Al 30catalyst is more acidic than the Si/Al 280 catalyst. The Si/Al 280catalyst produced more oxygenates and naphthenes, and less aromatics.FIG. 45 illustrates the liquid-phase product distribution as a functionof hydrocarbon type and number of carbons for acetone oligomerizationover H-ZSM-5 zeolite (Si/Al ratio 280). Under these conditions, thereaction did not quite go to completion; however, other conditions haveshown near-complete conversion is possible (see Example 5).

TABLE 4.1 Example 4 Reaction Conditions- Acetone-to-Hydrocarbon ReactorAcetone Flow Rate 10 mL liquid/h Catalyst Mass 6 g Weight Hourly SpaceVelocity (WHSV) 1.31 g reactant/(g catalyst · h) Pressure 1 atm (abs)Temperature (Max.) 330° C. Catalyst H-ZSM-5 (Si/Al 280)

TABLE 4.2 Product Distribution (wt %) Gas Liquid CH₄ 0.15% C5s 0.40% CO₂0.74% Acetone 23.33% C₂H₄ 1.19% C6s 11.54% C₂H₆ 0.00% C7s 5.95% C₃H₆2.27% C8s 8.16% C₃H₈ 0.31% C9s 13.88% CO 0.05% C10s 6.85% C4s 21.26%C11+ 3.92% Total 25.97 Total 74.03%

TABLE 4.3 Hydrocarbon Distribution in the Liquid (Gasoline) Fraction (wt%) Isomeric Naphthene Paraffins Oxygenates Olefins Compounds NaphthenesOlefinics Aromatics Unknown 0 15.894 9.374 1.01 17.865 3.862 41.26 2.942

Example 5 Acetone to Hydrocarbons (Si/Al 280)

Materials and Methods:

Liquid acetone was vaporized and added to the reactor operated using theconditions shown in Table 5.1. The product exiting the reactor wasseparated into two fractions: liquid and gas. The total mass of eachproduct was measured and the composition was determined by gaschromatography/mass spectroscopy (GC/MS).

Results:

Table 5.2 shows the product distribution. Of the total product, theliquid fraction (gasoline) was 86.16% and the gases were 13.82%. Table5.3 shows the classes of products in the liquid fraction. Tables 4.3 and5.3 report identical conditions, except for temperature. The highertemperature reduces the oxygenates and naphthenes, and increases thearomatics. FIG. 46 illustrates the liquid-phase product distribution asa function of hydrocarbon type and number of carbons for acetoneoligomerization over H-ZSM-5 zeolite (Si/Al ratio 280). In this example,the reaction went nearly to completion.

TABLE 5.1 Example 5 Reaction Conditions- Acetone-to-Hydrocarbon ReactorAcetone Flow Rate 10 mL liquid/h Catalyst Mass 6 g Weight Hourly SpaceVelocity (WHSV) 1.31 g reactant/(g catalyst · h) Pressure 1 atm (abs)Temperature (Max.) 400° C. Catalyst H-ZSM-5 (Si/Al 280)

TABLE 5.2 Product Distribution (wt %) Gas Liquid CH₄ 0.11% C5s 1.39% CO₂1.63% Acetone 0.72% C₂H₄ 1.49% C6s 8.94% C₂H₆ 0.00% C7s 13.92% C₃H₆1.63% C8s 30.54% C₃H₈ 1.00% C9s 17.18% CO 0.28% C10s 9.29% C4s 7.68%C11+ 4.18% Total 13.82 Total 86.16%

TABLE 5.3 Hydrocarbon Distribution in the Liquid (Gasoline) Fraction (wt%) Isomeric Naphthene Paraffins Oxygenates Olefins Compounds NaphthenesOlefinics Aromatics Unknown 0.548 4.583 2.26 1.083 3.772 4.359 68.9831.255

Example 6 Acetone and Hydrogen to Hydrocarbons (Si/Al 280)

Materials and Methods:

Hydrogen and vaporized acetone were added to the reactor operated usingthe conditions shown in Table 6.1. The product exiting the reactor wasseparated into two fractions: liquid and gas. The total mass of eachproduct was measured and the composition was determined by gaschromatography/mass spectroscopy (GC/MS).

Results:

Table 6.2 shows the product distribution. Of the total product, theliquid fraction (gasoline) was 80.63% and the gases were 19.38%. Theper-pass hydrogen conversion was 44.25%. Table 6.3 shows the classes ofproducts in the liquid fraction. Tables 5.3 and 6.3 report identicalconditions, except for the presence of hydrogen, which increasesaromatics. FIG. 47 illustrates the liquid-phase product distribution asa function of hydrocarbon type and number of carbons for acetone andhydrogen oligomerization over H-ZSM-5 zeolite (Si/Al ratio 280). In thisexample, the reaction went nearly to completion.

TABLE 6.1 Example 6 Reaction Conditions-Acetone-plus-Hydrogen-to-Hydrocarbon Reactor Acetone Flow Rate 10 mLliquid/h 0.13 mol/h Water Flow 0 Hydrogen 53 mL/min 0.13 mol/h RatioH₂/Acetone 1 molar ratio Pressure 1 atm (abs) Temperature (Max.) 400° C.Catalyst H-ZSM-5 (Si/Al 280)

TABLE 6.2 Product Distribution (wt %) Gas Liquid CH₄ 0.14% C5s 0.84% CO₂2.72% Acetone 4.05% C₂H₄ 2.31% C6s 11.54% C₂H₆ 0.00% C7s 15.81% C₃H₆2.56% C8s 18.71% C₃H₈ 1.00% C9s 11.39% CO 0.41% C10s 9.79% C4s 10.24%C11+ 8.50% Total 19.38% Total 80.63%

TABLE 6.3 Hydrocarbon Distribution in the Liquid (Gasoline) Fraction (wt%) Isomeric Naphthene Paraffins Oxygenates Olefins Compounds NaphthenesOlefinics Aromatics Unknown 0 8.688 3.103 0.295 4.853 3.209 77.83 1.582

Example 7 Acetic Acid To Hydrocarbons (Si/Al 280)

Materials and Methods:

Liquid acetic acid was vaporized and added to the reactor operated usingthe conditions shown in Table 7.1. The product exiting the reactor wasseparated into two fractions: liquid and gas. The total mass of eachproduct was measured and the composition was determined by gaschromatography/mass spectroscopy (GC/MS).

Results:

Table 7.2 shows the product distribution. Of the total product, theliquid fraction was 49.77% and the gases were 51.76%. FIG. 48illustrates the liquid-phase product distribution as a function ofhydrocarbon type and number of carbons for acetic acid oligomerizationover H-ZSM-5 zeolite (Si/Al ratio 280).

TABLE 7.1 Example 7 Reaction Conditions- Acetic-Acid-to-HydrocarbonReactor Acetic Acid Flow Rate 10 mL liquid/h Catalyst Mass 6 g WeightHourly Space Velocity (WHSV) 1.31 g reactant/(g catalyst · h) Pressure 1atm (abs) Temperature (Max.) 400° C. Catalyst H-ZSM-5 (Si/Al 280)

TABLE 7.2 Product Distribution (wt %) Gas Liquid CH₄ 0.13% Acetic acid29.53% CO₂ 33.99% 2-Propanone 8.195% C₂H₄ 0.23% Other Oxygenates 4.02%C₂H₆ 0.00% Aromatics 8.025% O₂ 0.00% Total 49.77% N₂ 0.00% H₂O 0.00%C₃H₆ 0.66% C₃H₈ 0.00% CO 0.66% C4s 16.09% Total 51.76%

Example 8 Acetic Acid and Hydrogen to Hydrocarbons (Si/Al 280)

Materials and Methods:

Hydrogen and vaporized acetic acid were added to the reactor operatedusing the conditions shown in Table 8.1. The product exiting the reactorwas separated into two fractions: liquid and gas. The total mass of eachproduct was measured and the composition was determined by gaschromatography/mass spectroscopy (GC/MS).

Results:

Table 8.2 shows the product distribution. Of the total product, theliquid fraction was 47.59% and the gases were 52.34%. The hydrogenconversion was 19.17%. FIG. 49 illustrates the liquid-phase distributionfor acetic acid and hydrogen oligomerization over H-ZSM-5 zeolite (Si/Alratio 280). In this example, a substantial portion of the acetic acidwas unreacted, so a longer residence time is needed.

TABLE 8.1 Example 8 Reaction Conditions-Acetic-Acid-plus-Hydrogen-to-Hydrocarbon Reactor Acetic Acid Flow Rate10 mL liquid/h Hydrogen Flow Rate 36 cm³/min Ratio Acid/H₂ 2 molar ratioCatalyst Mass 6 g Temperature (Max.) 410° C. Pressure 1 atm (abs)Catalyst H-ZSM-5 (Si/Al 280)

TABLE 8.2 Product distribution (wt %) Gas Liquid CH₄ 0.24% Acetic Acid40.48% CO₂ 30.52% 2-Propanone 4.90% C₂H₄ 0.00% Other Oxygenates 0.90%C₂H₆ 0.00% Aromatics 1.31% C₃H₆ 3.17% Total 47.59 C₃H₈ 0.00% CO 0.37%Isobutane 0.00% Butane 18.04% Isobutylene 0.00% 1-Butene 0.00% Total52.34

Example 9 Ammonium Acetate to Hydrocarbons (Si/Al 280)

Materials and Methods:

An aqueous solution of 20% ammonium was vaporized and added to thereactor operated using the conditions shown in Table 9.1. The productexiting the reactor was separated into two fractions: liquid and gas.The total mass of each product was measured and the composition wasdetermined by gas chromatography/mass spectroscopy (GC/MS).

Results:

Table 9.2 shows the dominant liquid-phase products. FIG. 50 illustratesthe liquid-phase distribution as for ammonium acetate oligomerizationover H-ZSM-5 zeolite (Si/Al ratio 280). The aromatics are molecules with8 and 12 carbons.

TABLE 9.1 Example 9 Reaction Conditions- Ammonium-Acetate-to-HydrocarbonReactor Ammonium Acetate Solution 50 mL/h Ammonium Acetate Concentration20% (w/w) Ammonium Acetate Addition Rate 10 g/h Catalyst Mass 6 g WeightHourly Space Velocity (WHSV) 1.66 g reactant/(g catalyst · h)Temperature (Max.) 400° C. Pressure 1 atm (abs) Catalyst H-ZSM-5 (Si/Al280)

TABLE 9.2 Dominant Compounds in Liquid Phase Acetonitrile 42.70 Aceticacid 21.29 Acetone 16.80 Total 80.79

While preferred embodiments of the invention have been shown anddescribed, modifications thereof can be made by one skilled in the artwithout departing from the spirit and teachings of the invention. Theembodiments described herein are exemplary only, and are not intended tobe limiting. Many variations and modifications of the inventiondisclosed herein are possible and are within the scope of the invention.Where numerical ranges or limitations are expressly stated, such expressranges or limitations should be understood to include iterative rangesor limitations of like magnitude falling within the expressly statedranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4,etc.; greater than 0.10 includes 0.11, 0.12, 0.13, and so forth). Use ofthe term “optionally” with respect to any element of a claim is intendedto mean that the subject element is required, or alternatively, is notrequired. Both alternatives are intended to be within the scope of theclaim. Use of broader terms such as comprises, includes, having, etc.should be understood to provide support for narrower terms such asconsisting of, consisting essentially of, comprised substantially of,and the like.

Modifications, additions, or omissions may be made to the systems andapparatuses described herein without departing from the scope of theinvention. The components of the systems and apparatuses may beintegrated or separated. Moreover, the operations of the systems andapparatuses may be performed by more, fewer, or other components. Themethods may include more, fewer, or other steps. Additionally, steps maybe performed in any suitable order.

Accordingly, the scope of protection is not limited by the descriptionset out above but is only limited by the claims which follow, that scopeincluding all equivalents of the subject matter of the claims. Each andevery claim is incorporated into the specification as an embodiment ofthe present invention. Thus, the claims are a further description andare an addition to the preferred embodiments of the present invention.The disclosures of all patents, patent applications, and publicationscited herein are hereby incorporated by reference, to the extent theyprovide exemplary, procedural or other details supplementary to thoseset forth herein.

We claim:
 1. A method of producing alcohols from biomass, the methodcomprising: converting biomass into a carboxylic acid; reacting thecarboxylic acid with an olefin to produce an ester; and hydrogenolyzingthe ester to produce alcohol.
 2. The method of claim 1, wherein reactingthe carboxylic acid with an olefin to produce an ester andhydrogenolyzing the ester to produce an alcohol are carried out in thesame reactor.
 3. The method of claim 2, wherein reacting the carboxylicacid with an olefin to produce an ester and hydrogenolyzing the ester toproduce an alcohol are carried out with one catalyst.
 4. The method ofclaim 1, further comprising: dehydrating at least a portion of thealcohol to produce an olefin feed, at least a portion of the olefin feedproviding the olefin that reacts with the carboxylic acid to produce theester.
 5. The method of claim 4, wherein reacting the carboxylic acidwith an olefin to produce an ester and hydrogenolyzing the ester toproduce an alcohol are carried out in the same reactor.
 6. The method ofclaim 5, wherein reacting the carboxylic acid with an olefin to producean ester and hydrogenolyzing the ester to produce an alcohol are carriedout with one catalyst.
 7. The method of claim 1, further comprising:reacting at least a portion of the alcohol at suitable conditions toproduce hydrocarbons.
 8. The method of claim 1, wherein converting thebiomass into a carboxylic acid further comprises: fermenting the biomassto yield a liquid fermentation broth comprising water and carboxylatesalts; dewatering the liquid fermentation broth to separate the waterfrom the carboxylate salts; and converting the carboxylate salts intocarboxylic acids.
 9. The method of claim 1, furthering comprising:converting the alcohol into a hydrocarbon.
 10. The method of claim 9,wherein reacting the carboxylic acid with an olefin to produce an esterand hydrogenolyzing the ester to produce an alcohol are carried out inthe same reactor.
 11. The method of claim 10, wherein reacting thecarboxylic acid with an olefin to produce an ester and hydrogenolyzingthe ester to produce an alcohol are carried out with one catalyst. 12.The method of claim 9, wherein converting the alcohol into a hydrocarboncomprises an oligomerization process.
 13. The method of claim 12,wherein the converting the alcohol into a hydrocarbon comprises:dehydrating at least a portion of the alcohol to produce an olefin feed;and oligomerizing at least a portion of the olefin feed to produce thehydrocarbon.